On 05 Aug 2015 09:20, Paul Eggert wrote:
> On 08/05/2015 03:22 AM, keld@keldix.com wrote:
> > For countries with more timezones, the locale data helps narrowing down the
> > choices. And there are not that many countries with more than 1 timezone,
> > eg USA, Canada, Russia and Greenland. Many big countries like China and India
> > only have 1 timezone
> 
> Actually, China has two time zones: tzdata's Asia/Shanghai and 
> Asia/Urumqi both reflect officially-kept time.  Even Germany has more 
> than one tzdata entry, due to the a difference in post-1970 history of 
> timekeeping in its Swiss enclaves.  So the problem of many time zones 
> for one locale is bigger than what you're suggesting, even if we ignore 
> traveling users (which is a pretty big class to ignore).

a cursory search shows many more countries as well:
Canada, USA, Mexico, Brazil, Australia, Russia, Mongolia, Kazakhstan,
Democratic Republic of Congo, Indonesia, Greenland (does that mean Denmark
too?).  that's at least 16% of the world's population (35% if you count
China).

and that's just for the current period of time.  as you highlight, if you
look back historically, there are other countries that spanned timezones.

locales also are not strictly defined by country borders which means the
timezone spans are even higher (i'm not counting people who travel).
-mike